scholarly journals Thermodynamic analysis of the double Brayton cycle with the use of oxy combustion and capture of CO2

2013 ◽  
Vol 34 (2) ◽  
pp. 23-38 ◽  
Author(s):  
Paweł Ziółkowski ◽  
Witold Zakrzewski ◽  
Oktawia Kaczmarczyk ◽  
Janusz Badur
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Compression Ratio ◽  
Negative Pressure ◽  
Condensation Process ◽  
Brayton Cycle

Abstract In this paper, thermodynamic analysis of a proposed innovative double Brayton cycle with the use of oxy combustion and capture of CO2, is presented. For that purpose, the computation flow mechanics (CFM) approach has been developed. The double Brayton cycle (DBC) consists of primary Brayton and secondary inverse Brayton cycle. Inversion means that the role of the compressor and the gas turbine is changed and firstly we have expansion before compression. Additionally, the workingfluid in the DBC with the use of oxy combustion and CO2 capture contains a great amount of H2O and CO2, and the condensation process of steam (H2O) overlaps in negative pressure conditions. The analysis has been done for variants values of the compression ratio, which determines the lowest pressure in the double Brayton cycle.

THERMODYNAMIC ANALYSIS AND SYSTEM DESIGN OF THE SUPERCRITICAL CO2 BRAYTON CYCLE FOR WASTE HEAT RECOVERY OF GAS TURBINE

2020 ◽  
Vol 51 (2) ◽  
pp. 129-146
Author(s):  
Min Xie ◽  
Yong Hui Xie ◽  
Yichuan He ◽  
Aihua Dong ◽  
Chunwei Zhang ◽  
...  
Keyword(s):  
System Design ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Supercritical Co2 ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Brayton Cycle

Experience of negative pressure wound therapy over sternal wound healing: A retrospective review

WCET Journal ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 9-18
Author(s):  
Wai Sze Ho ◽  
Wai Kuen Lee ◽  
Ka Kay Chan ◽  
Choi Ching Fong
Keyword(s):  
Wound Healing ◽  
Negative Pressure ◽  
Negative Pressure Wound Therapy ◽  
Assessment Tool ◽  
Wound Care ◽  
Wound Therapy ◽  
Treatment Pathways ◽  
Wound Assessment ◽  
One Year

Objectives The aim of this study was to retrospectively review the effectiveness of negative pressure wound therapy (NPWT) in sternal wound healing with the use of the validated Bates-Jensen Wound Assessment Tool (BWAT), and explore the role of NPWT over sternal wounds and future treatment pathways. Methods Data was gathered from patients' medical records and the institution's database clinical management system. Seventeen subjects, who had undergone cardiothoracic surgeries and subsequently consulted the wound care team in one year were reviewed. Fourteen of them were included in the analysis. Healing improvement of each sternal wound under continuous NPWT and continuous conventional dressings was studied. In total, 23 continuous NPWT and 13 conventional dressing episodes were analysed with the BWAT. Results Among conventional dressing episodes, sternal wound improvement was 2.5–3% over 10 days to 3.5 weeks, whereas 4–5% sternal healing was achieved in 5 days to 2 weeks with sternal wire presence. Better healing at 11% in 1 week by conventional dressing was attained after sternal wire removal. In NPWT episodes, 8–29%, 13–24%, and 15–46% of healing was observed in 2 weeks, 3.5 to 5 weeks and 6 to 7 weeks, respectively. Only 39% wound healing was acquired at the 13th week of NPWT in one subject. With sternal wire present, 6%–29% wound healing progress was achieved by NPWT in 1–4 weeks, and 16–23% wound improvement in 2 to 4.5 weeks by NWPT after further surgical debridement. After sternal wire removal, 6–34% sternal wound healing occurred by continuous NPWT for 1–2 weeks, and maximum healing at 46% after 2.5 weeks of NPWT were observed. Conclusions Better wound healing was achieved in the NPWT group in comparison to conventional dressings alone. However, suboptimal sternal wound healing by NPWT alone was observed. Removal of sternal wire may improve the effectiveness of NPWT. Successful tertiary closure after NPWT among subjects supports the important bridging role of NPWT in sternal wound healing. Factors causing stagnant sternal wound healing by NPWT alone are discussed.

The role of angiopoetic factors in wound healing among patients with diabetes treated with negative-pressure wound therapy

Leczenie Ran ◽  
2015 ◽  
Vol 11 (4) ◽  
pp. 171-178
Author(s):  
Beata Mrozikiewicz-Rakowska ◽  
Joanna Kania ◽  
Ewelina Bucior ◽  
Adriana Nowak ◽  
Tomasz Grzela ◽  
...  
Keyword(s):  
Wound Healing ◽  
Negative Pressure ◽  
Negative Pressure Wound Therapy ◽  
Wound Therapy ◽  
Patients With Diabetes

Modelling the Air-Cooled Gas Turbine: Part 1 — General Thermodynamics

2001 ◽  
Author(s):  
J. B. Young ◽  
R. C. Wilcock
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Real Gas ◽  
Thermal Mixing ◽  
Ideal Gases ◽  
Formal Framework ◽  
Considerable Simplification ◽  
Cycle Efficiency ◽  
General Thermodynamics

This paper is Part I of a study concerned with developing a formal framework for modelling air-cooled gas turbine cycles and deals with basic thermodynamic issues. Such cycles involve gas mixtures with varying composition which must be modelled realistically. A possible approach is to define just two components, air and gas, the latter being the products of stoichiometric combustion of the fuel with air. If these components can be represented as ideal gases, the entropy increase due to compositional mixing, although a true exergy loss, can be ignored for the purpose of performance prediction. This provides considerable simplification. Consideration of three idealised simple cycles shows that the introduction of cooling with an associated thermal mixing loss does not necessarily result in a loss of cycle efficiency. This is no longer true when real gas properties and turbomachinery losses are included. The analysis clarifies the role of the cooling losses and shows the importance of assessing performance in the context of the complete cycle. There is a strong case for representing the cooling losses in terms of irreversible entropy production as this provides a formalised framework, clarifies the modelling difficulties and aids physical interpretation. Results are presented which show the effects on performance of varying cooling flowrates and cooling losses. A comparison between simple and reheat cycles highlights the rôle of the thermal mixing loss. Detailed modelling of the heat transfer and cooling losses is discussed in Part II of this paper.

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